Latch mechanism



Oct. 13, 1953 Filed July 10, 1948 R; MARPLE LATCH MECHANISM 3 Sheets-Sheet l R. MARPLE LATCH MECHANISM Oct. 13, 1953 3 Sheets-Sheet 2 Filed July 10, 1948 R. MARPLE LATCH MECHANISM Oct. 13, 1953 3 Sheets-Sheet 5 Filed July 10, 1948 INVENTOR. Kaila )f a Patented Oct. 13, 1953 UN 1 TE D STATES PATENT OFF'ICIE LATCH 'MECHANISM The present invention relates to latching 'IdG- vices for closures and in :particular provides an improved latch construction for vehicle doors. In certain or its "aspects the present invention provides improvements upon "and modifications of the structures disclosed and claimed in app'lican'ts United States Patent Nos. "2,195,179, 2,301,558 and2,"3'0'1,5'60.

The principal objects of "the present invention are to provide an improved latch of the above generally indicated character particularly adapted for butnotlimited to use in connection with vehicle "doors, -'characterized as 'being simple in construction, economical of manufacture and extremely durable and e'fiicien't'in operation; to provide alatch of the rotarybolt'type embodying improved'means operable from within the vehicle for locking the inside and outside handles against actuation; to "provide improved means actuated by the bolt 'forreleasing theloc'king means; to provide a 'door latch embodying improved means operable by -a key station for locking the latch against opening by the outside "door handle and to generally improve theconstruction andopera- "tion of 'vehicl'edoor latches.

"With'the above as'well 'asother-objects in view which appear in the following description "and appended claims, a preferred but illustrative embodiment of the invention as shown -in the accompanying drawings throughout the several views of which corresponding reference characters are "used to designate -corresponding parts and -in which:

Figure 1 is 'a view in elevation illustrating the application of the'inventi'on to automo'biledoors;

.Fig. 2 isa view in perspective'of the improved latch 'mechanism;

Fig. 3 is a view taken'substantially along the -lines 3+3 of Fig.1;

Fig. 4 is aview taken substantially along the lines i4 of 'Fig. '3;

Fig. '5 is aviewtaken substantially along the lines 5- 5 of Fig. 3;

Fig. '6 isf'a view taken substantially along the lines 6-"6 of Fig. '3;

Fig. 7is a'partial view showing'a modified form of .the invention;

Fig. 8 is a view similar to Fig. 6 but showing themodifiediorm o'f latch shown in Fig. 7

Fig. 9is aviews'imila-r toFi'g. 8 but showing the latch in lockedposition; and

Fig. 10 is an exploded perspective view of a portion of the locking mechanism.

The improved latch which '-is secured *within a door "2 of the associated "vehicle I comprises generally a casing 4, a plurality of cams :ordogs-des- .ignated:generally aszG for holding a bolt 15 against rotation :in :a door-opening :direction; .an outside roperaited rroll hack means designated :as a whole as .8.fhr1releasing the dogs '5 and the bolt 5 .in response to movement of the conventional out- :side :handle 19a; and .a retracting member I?) which may be connected toitheaconventional inside zioorhandle .or 'the like (xnotrshown), tore- .Llease .the :dogs a from .operative engagement with sthesholtzii. The keeper l2 which is describedin more detail below sisrsuitablyzsecured to the door .pillar 1:4 'as ."by means "of .the .plate H5.

The halt -5 is rotatablyionrnaled inzthe latch casing upon pin for trunnion 2.9, one :end of which its supported :in the ifiange i2 2 of ahousing '25 which is :suitably secured to the .fiange 28 of the casing =4 as :by'tabs struck from the ifiange 2 13. The .otheriend .of 'thepin 2G :is supported in a Ideek .2 8 'iWhiCh is suitably secured :to the inner iiace of the :fiange J26.

The :bolt I5 :is iformedto provide a keeperengaging portion 53!] "which :projects externally of the lock :casing 41ior cooperation with the keeper 4.2:; :anzinner or ream-engaging :portion 32 and a separate fin :or vane .34 which is somewhat larger in diameter than the :portions 39 and =32 .and serves .to substantially close the opening 3 5 which zprovided in the fiange zii of the casing l 'toiaecommodate the bolt. Tlheiower half of the outwardly projecting portion 30 of :the bolt .5 :is :sub-

stantially enclosed by the previously mentioned housing 24, which is given a substantially semi- =cylindricall form for this purpose.

'Aswill'be'seen in Fig.4, the outer portion 3a of the :bolt :5 is formed "to provide a plurality of :radia'lly extending, equiangularly spaced, keeperenga'ging teeth or projections 360., any one of which is effective, as described hereinafter, to :cooperate with the safety catch it associated with the keeper 1?, or keeper portionfiZ, to hold the door in either :the partially "closed or safety position, :or :in the fully olosed position, respectively. :It will :be appreciated that the angular ispacingrbetween the projections or teeth eta rel- -:ative to Ltheispacing between the safety catch it and the laeeperportion-dfi is such that'the bolt =5- canrol1 overor across the keeper ina manner .similar to the-cooperation :between-a ,gear and a :rack.

As appears :in Figs. 2 and 5, the .inner :portion 32'of the bolt B is iformed to prov ide a number of dog-engaging 'tee'thor projections 32a, the number and angular spacing between "which :correspon'dstotheinunib'er and angular ..spacing of the keeper-engaging teeth a. The teeth 32a, however, are angularly displaced from the teeth 30a. This relation results in reducing the space requirements for the lock since the positioning of the cam can thus be determined independently of the rotative position of the teeth 30a. Each tooth 32a is formed to provide a generally radially extending, cam-engaging portion 44 and a locking portion 46, the purpose of which will be described hereinafter.

The dogs 6 are provided to cooperate with the latching portion 46 of the bolt 5 to hold the bolt 5 against rotation in a clockwise or door-opening direction as viewed in Fig. 2 or the counterclockwise direction as viewed in Fig. 5. It is preferred to use a plurality of such dogs of progressively increasing length to provide a take-up action for the latch as will be described below. In the present instance three such dogs are illustrated although a small or larger number may be utilized if desired.

The three dogs designated as a whole at 6, are rotatably supported in the latch casing upon a pin or trunnion 50 which extends parallel to but is spaced from the previously mentioned bolt-supporting pin 20. The outer end of the pin 50 is supported in a member 52, the inner flanges 54 whereof are secured to the inner face of the casing flange 26 as by means of tabs 55, one of which is shown in Fig. 2, which are struck from the flange 26 and project through apertures in the flange 54, after which they are bent downwardly to secure the flange 54 to the flange 26. The outwardly extending body portion of the member 52 serves as most clearly appears in Figs. 3 and 4 as a dovetail member. The inner end of the pin 50 is supported in the previously-mentioned supplemental casing member or deck 28. Each of the three dogs, which are individually designated as 56, 58, and 60, includes a downwardly extending body which terminates in a laterally offset foot. The cam 56 is slightly longer than the cam 58 and the cam 58 in turn is slightly longer than the cam 60. Each of the cams 56, 58, and 60 is provided with a biasing spring 62 individual thereto. One end of each spring is secured between a pair of lugs 64 which are inwardly struck from the casing flange 26 and the free end of each spring 62 bears against the edge of the associated cam and so continuously urges it in a counterclockwise or looking direction as viewed in Fig. 2.

The outside roll back, designated as a whole at 8, embodies an arrangement designed to prevent rattling. In the illustrated instance the outside roll back 8 comprises a pair of roll back members I and 9 arranged in face-to-face relation and each having an axially extending boss II which extends outwardly therefrom in directions opposite to the registering faces of the members 'I and 9. The roll back members I and 9 are provided with squared openings therein which are slightly angularly offset from each other and which are dimensioned to relatively freely receive the squared spindle 68 associated with the outside operating handle Be. With this relation, the spindle 68 is inserted through the roll back members l and 9 when they are slightly angularly ofiset from each other. When later they are engaged by the slide I0 which is constantly urged in an upward direction by a spring 72 one of the members I or 9 will be in engagement with the upper flange I4 of the member I0 and urged in a counterclockwise direction (Fig. 2) while the other of the members I or 9 will be engaged by a downturned tab I5 of the deck 28 and held against such counterclockwise rotation whereby the members i and 9 tend to bind on the squared spindle 68 so that it is prevented from rattling upon being subjected to vibration.

Clockwise rotation of the roll back means 8 by means of the spindle 66 retracts the holding cams 5656-60 through the action of a slide 10. The slide I0 is guided for its reciprocal sliding movement by means of a pin 02 carried by the base 84 of the casing 4 which pin extends through an elongated slot 06 of the slide I0. The lower end 00 of the slide I6 is guided between two downturned feet of a deck 90 suitably carried by the base 84 adjacent its lower end portion. A spring 72 continuously urges slide I0 upwardly, and normally holds it against the roll back 8.

Slide I0 has a laterally turned foot I4 for engagement by the roll back 8, and a laterally turned foot I6 which engages the nose 18 of the dog 60 and thereby rotates the dogs 56, 58, and 60 in a clockwise direction out of holding engagement with the rotatable bolt 5. The movement of the dogs 56 and 53 is caused by movement of the dog 60 by means of a flange which lies behind the rear face of the dogs 56 and 53.

The retracting member ID is pivotally supported on the pin 62 and may be rotated by means of an inside door handle (not shown, but of the type which is continuously urged to a center position but may be moved therefrom in either a locking direction or a door-opening direction) suitably connected to the pin 9| carried by the member :0. The member I0 has a nose 92 which is engageable with the nose I8 of the dog 60 whereby counterclockwise rotation of the member it will rotate the dogs 6 in a clockwise direction for releasing the rotary bolt 5.

Locking means, generally designated I00, is carried by the base 84 and comprises a first pivotal lever I02, pivotally mounted on the pin 82, and having a foot I04 which is movable, upon clockwise rotation of the lever I02, from the position shown in Fig. 2 into a position in which it lies in the downward path of movement of the flange M of slide I0, thus preventing downward movement thereof under control of the outside roll back 8, The lever I02 has a second arm I06 which is pivotally connected by means of pin 03 to a link I I0 which extends downwardly therefrom and is pivotally secured at its lower end to pin I I2 carried by a key-operated member I I4. The member H4 is carried by a member I I6 which has a central axial opening extending therethrough for receiving the end portion of a lock shaft extending from the key station H8 carried by the exterior surface of the door 2. The member I Hi has a radially enlarged central portion I20 and oppositely projecting axially extending cylindrical portions I22 and I24. The portion E24 extends completely through the member H4 and is journaled within an aperture in the base 64. The cylindrical portion I22 is received and journaled within an aperture in the deck 90. The member I I4 is provided with a pair of spaced outwardly turned abutments I26 and I26 which extend into the plane of the central portion I20 of the member II6. This central portion I20 is provided with a pair of diametrically opposite portions extending outwardly from the peripheral surface thereof one of which portions will, upon rotation of the member H6 by the key station I I6, move into engagement with one of the abutments I26 and 28 for rotation in a counterclockwise or clockwise direction of the member II4 actsgoeis foractuation'oi the link M50 and lever i0 2. 'l his just recited connection between the members PM and H6 is *to-provide a lost motion connection therewith so that upon :rotation 'of the key in the lock M8 for either looking or unlocking movement of the member 11 6, the key may be rotated back to its iinitial position and'removed from' the look without actuation-of the member 114. The opposite abutment is provided so that the "same part may be used in a la tch "of oppos'ite'hand.

In order that the locking mechanism M0 will be held in either its fully =unlocked-or1its"f1il1y locked position and to prevent rattling, an overcenter spring -3.2 is'provideii. One end of the spring l-32 is received within an aperture 134 of the base :84 while the other-end of the spring is received within-an aperture "res in'ithe lower end ofthe link M0. The locationnf the' apertures +34 and 13B iisso'chosen relative to the normal-movemerit zo'f'the lirik l l-ll that the resilient efiort "of the spring I32 -:will urge the link 110 in-a d-ownward-directionas seen in Figsy-Zand 6 and will urge the link -I in an upward position subsequent to upward movement :of the link HO to place the lever Ill-2 in its blockingrposition with respect to the flange 14. The member do has a shoulder 13!; which is engage'able with the:head of the pin 408 upon clockwise rotation of the member H! to rotate the lever E02 clockwise from its pcsitionshownin Fig. 2, into its blocking position. Such operation .of the locking mechanism we is accomp ished by momentarily moving .the inside doorihandle Oflthe'VhiClE door Zin'a direction opposite to the direction "required for'rel'easin'vof the latch.

In order that the locking'mechanism .lflifi inlay be automatically moved to its .unlocked:position, the :arm [lit-of thelever I102 is so shaped that upon clockwise rotation :of the lever its to its locked position, the arm "it "will be located .beneath the foot 18. .As will be made clear hereafter, .upon .door-rclosing ,movement the bolt :5 will be rotated in a counterclockwise :direction as shown in Figs. 12 sand 4 whereby the dogs 6 are rotated clockwise about the pin 5.8 causing the foot 18 thereof .to move.downwardlyeengagin :the arm :lllfi'and rotating theilever H32 inatcounterclockwise direction toward its unlockingiposition and sufiiciently far so that "the overcenterspring 132 will cause "the locking mechanism $0.0 :to be moved :to :andimaintained ,in;its unlockedzposition as:showninFis.:2.

Referring particularly to Fig. eythe keeper 12 comprises a ibody'which may bezandpreier-ablyis formed as a relatively heavy metal stamping which is formed to define the previously-mentioned bolt-engaging surface 42. 'The previously mentioned safety catch 40 .is and may he formed of a die casting or the like :andris tpivotally supported by :a .pin I54 which extends between and is supported in the opposite side walls of the keeper 12. A spring I56 :is connected between the catch -40 and the keeper body and continuously urges the safetv ca'tch All to active position as shown in Fig. 4. It will .be noted that the otherwise continuous body of the .keeper [,2 iscut away as indicatedat I55 to affordaslot or-opening through which thesafety catch All may move from the active position shown .in .Fig. 4 to .a retired position. 'It will also be noted that the back of the safety catch Ml abuts 'the portion 1'59 of the body of the keeper l2 so that such portion 159 forms a limit stop to the rotation thereof under-the influence of the spring I56.

As also clearly appears in Fig. 4 when the-door is in a closed position, the keeper 1 2 is .in :a 'posir tionbetween the rotary bolt iandthepreviouslymentioned dovetail member 52, the upper surfaceofthe keeper 12 as well as the under-surface of the dovetail member :52 downwardly inclined in the direction of the door-closing movement. "With this relation the dovetail member tends to serve as a stop to the movement of the keeper I2 in the leftward or door-closing directionas influenced by thebolt-5. These members 5, l2 and 52 accordingly function in accordance with the functioning of the usual separately formed :dovetails 'usually associated with "locks of the conventional slidablebolt type and permit suchseparate dovetail structures to be dispensed with.

Considering the operation *as a whole of the above described construction, the parts areshown in Figs. "2, *3, 4, 5, and 6 in positions occupied thereby when the door 'is in "a fully or tightly closed position and with the locking'mechanism H30 in unlocked position. 'Under these circumstances the upper tooth 30a of the outer portion 30 of the rotary bolt 5 bears solidly against the cooperating surface 32 of the keeper l2 forcibly wedging the latter between the bolt 5 and the dovetail member 52. At the same time the foot of the longest dog 56 bears solidly against the upper substantially horizontally 'disposed'locking surface 46 associated with the inner portion of the bolt 5. Cam is thus effective to entirely prevent any clockwise rotation of the bolt 5 so that the door is positivelyhe'ldin the "just-mentioned'fully'or tightly'closed position.

To-open the :door, the outside roll back 8 as" sociated with the door handle ta may 'be rotated torotate the outside roll back 8 ina clockwise direction shownin Fig. -2. Such rotation causes the link it to be moved downwardly whereby its nose 'l'fi-engages the nose 1 f the dogst rotating these dogs Sin a clockwise direction out of holding engagement with the bolt 5 whereby the bolt 5 is free to rotate. Upon anopening force being applied to the door '2 the bolt will rotate in .a clockwise direction as seen in :Fig. 4 permitting the door to be opened upon its hinges. If now insteadof operating the outsidedoor handle, the iinsi'de door handle is operated a :direction to .rotate'the link [8 'in'a clockwise direction, its -noset92 engages the nose E8 of the dogs rotating the dogs .6 in a clockwise direction thereby releasing the .bolt for the previously-mentioned dooreopeningmovement.

Assuming snow .that it is desired to place the lockingymechanism 1389 in its locked position, a key maybe placed in .thekey station Mil and:-ro .tated in .a JdlEBLiiiOll to rotate the member Hi3 counterclockwise as seen in Fig. The iprojection 1:31 then engages the projection i225 rotating the member J M in a counterclockwise direction which acts through pin l2 carried thereby to move the link it!) upwardly. Upwardmovement of the link 'I Hi rotates the lever :clockwise whereby "the foot 1M thereof is moved into a position underlying the flange M whereby movement of the slide it downwardly will be pr vented. i'Ihe lock mechanism its may also be moved to itslocked position .by movement of the inner door handle in a direction opposite from that mentioned above for door-opening movement whereby the link if] is rotated in a clockwise direction causing the projection 533 to engage the pin W8 and rotate the lever Hi2 in a clockwise direction causing the foot 164 to move to its blocking'position in which it underlies the flanged-4 of the slide 10.

"With-the locking mechanism W0 in'this locked position, downward movement of the slide I will be prevented and since the outside roll back 8 acts through this slide I0 and causes a downward movement thereof to release the dogs 5, the locking mechanism I00 prevents such release of the dogs 6 and the door cannot be opened by means of the outside door handle. Such locking position of the mechanism I 00 will not aifect operation of the latch from the inside door handle since the inside door handle acts on the link I0 which directly engages the foot 18 of the dogs 6 for rotation of the dog 6 and does not act through the slide 70. Such operation of the dogs 6 by the inner door handle through the link I0 will effect an unlocking movement of the locking mechanism I00. This unlocking movement is caused by the engagement of the lower surface of the foot 18 with the arm I06 so that when the came are rotated clockwise by the link I0 the undersurface of the foot 78, due to its engagement with the arm I05, will rotate the link I02 in a clockwise direction past the overcenter condition of the spring i2 2 whereby the locking mechanism I 00 will be moved to the unlocked position shown in Fig. 2. It may thus now be seen that dooropening movement by the inside door handle will cause the locking mechanism I00 to be moved to unlocked position.

If now the locking mechanism I00 has been moved to locked position (either by the key station IE0 or lever I0) and it is now desired to open the door from the exterior of the car, it is first necessary to insert a key in the locking station H8 and then rotate the key in a direction whereby the member H6 is rotated clockwise so that its abutment I30 engages the abutment I28 of the member Il4. Subsequent clockwise rotation of the member H0 rotates the member II4 clockwise to move the linkage II 0 downwardly whereby the lever I02 pivotally connected with the arm IIO will rotate counterclockwise into the position shown in Fig. 2. This renders the outside roll back 8 effective to act through the slide 70 for releasing the dogs 6 as above described.

Suppose that the locking mechanism I00 is in its locked position and the door is open and it is desired to close the door. Upon door-closing movement, the bolt 5 moves to the right relative to the keeper I2 as viewed in Fig. 4. As the door approaches the partially closed position corresponding to the conventional safety position, the safety catch 40 engages the right-hand face of the upper tooth 30a associated with the bolt 5. Continued door-closing movement causes the catch 40 to apply a rotative force to the bolt 5.

The springs 02, however, associated with the dogs are stronger than the spring I56 associated with the safety catch 40 so that no rotative movement of the bolt occurs. Instead the safety catch 40 rotates in a counterclockwise direction relative to the keeper 40 to a retired position in which the tooth may be moved past the keeper I2. As soon as the end of the safety catch 40 is passed by the upper bolt tooth, the springs I56 associated therewith is rendered effective to cause the safety catch to return to the active position shown in Fig. 4 in which it is effective to cooperate with the left-hand face of the upper bolt tooth 30a and positively prevent the door from again being fully open without again actuating the dogs 6 to release the bolt 5.

If the door-closing movement is continued beyond the safety position, just described, the sloping face I60 of the keeper I2 is brought into engagement with the right-hand face of the upper bolt tooth 30a and applies a positive rotative force of the bolt 5. Due to the fact that the boltholding effect of the dogs results from the cooperation between the teeth thereof and the bolt faces and not from the strength of the biasing spring 62, it is possible to utilize springs 62 which are relatively weak. Accordingly a minimum door-closing force is required to render the keeper face I effective to rotate the bolt 5 in a counterclockwise direction as viewed in Fig. 4.

During such movement a leading face 44 of an inner bolt tooth 32a bears against the rear edges of the cams and turns these dogs from the position shown in Fig. 2 to positions corresponding to positions in which the dogs 6 are rotated clockwise to permit a tooth projection to pass below the feet of the cams 56, 58, and 60. When the door reaches a substantial closed position, the just-mentioned inner bolt tooth face 44 passes beyond the heel of the shorter dog 60 permitting the latter to ride up over the rounded ends of the dog-engaging bolt face 46. As soon as this action takes place the spring 62 associated with the dog 60 becomes effective to rotate the latter in a counterclockwise direction as viewed in Fig. 2 and forcibly continues the rotation of the bolt 5 in a counterclockwise or door-closing direction. At slightly spaced stages in the continued doorclosing movement, the bolt face 44 successively passes beyond the heels of the dogs 58 and 56 rendering the springs 62 associated with these dogs successively effective to continue the counterclockwise or door-closing rotation of the bolt 5. The dogs 56 and 58 may be expected in the fully closed position of the door to occupy the full blocking position described with reference to cam 60. Reviewing the door-closing operation of the latch mechanism upon door-closing movement, it will be noted that the dog 60 is rotated clockwise which will cause its foot I8 to be moved downwardly and engage the arm I06 of the lever I02 for rotating the lever I02 in a counterclockwise direction and the mechanism I00 to unlocked position similarly as described with respect to the downward movement of the foot I8 under operation of the link I0 controlled by the inner door handle.

From the foregoing it will be appreciated that the present invention provides an extremely effective structure which is simple and economical of manufacture and which is exceptionally efficient and satisfactory in operation. It will also be appreciated that the specifically described embodiment permits the latch mechanism to be locked from either inside of the vehicle by means of the inside door handle or externally of the vehicle by means of the key station H8 and for the same to be unlocked either by means of the inner door handle or of the key station irrespective of one of these two elements which was used to effect locking of the latch mechanism.

In the modified form of the invention shown in Figs. 7, 8, and 9, the latch is carried in a casing 4a having a flange 25a and a base portion 84a, a rotary bolt 5, a locking mechanism I00a, an outside roll back 0a, an inside retracting member I0a continually biased to its neutral or shown positions by an inside door handle (not shown),

and dogs (not shown) releasably holding the bolt 5 against rotation. In this modification the outside roll back 8a comprises a lever 200 pivoted on .a pin 202 carried by the flange 26a. The lever 200 has an arcuate aperture 204 through which projects a pin 206 carried by the flange 26a member 2.58: which is. pivotally secured to the.

lever 2M1: asby m'eans'of pin 210 which not only pivotally connects the members together but forms. a partial guide for the movement of the slide 208. The other endof the slide 208 is provided with an elongated aperture 212 which receives a pin 214 carried by the flange 26a. In this: manner the slide. 298 is guided for reciprocal movement and the limits of the elongated aperture 2 l2 provide the limits of reciprocal mo ement of the slide 2082 The link 20!! has a nose 216 which is engageable with the upper surface of a flange 2l8 of a slide-10a. The slide 10a is suitably carried for sliding motion by the base 84a and is provided with a foot" Tea which is engageable with a foot ofthe dog means 6 (not'shownY which releasably holds the rotary bolt 5. The slide Tlla acts unon do nward mo eme t the same as the slide!!! for releasin the dog means fia' permittin rotation of the bolt 5';

The lever lfiza is of somewhat different shape than the previously described lever "92 and is provided with an abutment lMa which is movable'upon counterclockwiserotation of the lever l Za, into the path of move ent of a foot 2I9 whereby the outsideroll back is prevented from mov ng the slide Ilia downwardly sufiicient to rotate the dog means 6:; associated with the bolt 5 for releasing the bolt 5 for rotary mo ement.

The locking mec anism [Elsa is provided with the overcenter spring I32, a link Ma and the members H4 and HS-for actuation from an outside located kev stat on. The retracting member Illa is o erable fromthe inside door handle b means o the usual conne ting element'whereby itsnose; 92a is en a eable ith the foot of the do s associated with the bolt 5 for rotation o the do s or releasing this bolt 5. In this modification the member I Ila is not provided with an arm corresponding to the arm E38 of the member Ill and therefore the locking mechanism Idea i not actuatable by movement of the inside door handle. In this modification, the lever 102a is provided with a proiection which is pivotally connected to a locking rod 220 which may extend upwardly between the inner and outer door panels and upwardly through the garnish mold (not shown) associated with the vehicle door. Downward movement of the rod 22!! rotates the lever Him. in a counterclockwise direction causing its portion 1184a to move into blocking position with respect to the foot 2l9. Actuation of the locking mechanism liltla by means of the key station will be similar to that described above in connection with the form of the invention shown in Fig. 2. The link Hlla is provided with an upward projecting portion 222 which, when the locking mechanism Hills is moved to its locking position, will be located in the downward path of movement of the foot 73a of the dogs associated with the bolt 5 upon rotation of the dogs out of holding position with respect to the bolt 5 in the manner described above, whereby closing movement of the door with the latch in locked position will cause unlocking movement of the locking mechanism llilla. Similarly the locking mechanism Idea will be moved to unlocked position upon movement of the dogs for releasing the rotary bolt 5 by means of the retracting member Ella in the manner similar to that recited above.

What is claimed and is desired to be secured by United States Letters-Patent. is as follows:

1; In.a latch mechanism, a bolt, means for releasably'holding saidbolt, a roll back mechanism operatively connected to said holding means and actuatable to actuate said holding means for releasing said bolt, a blocking lever having a first position in which it acts to render said roll back mechanismin-effective and having a second posi-v tionin which it is inefiective to render said roll back mechanism ineffective, a rotatable key actuated member. normally maintained in afirst position. but rotatable into a second and a third position, a secondlever having lost motion connection' with said key member, a link pivotally connectedat one portion to said blocking lever and. a second portion. to. saidv secondv lever, said key member being. operable uponmovernent from he said first; tov its. said second. position to pass.- through said lost motionand actuate said secondv leverv to'actuate saidlink to move said blocking lever to its said first. position andoperable upon movement from its said first position to its said third position to pass through said lost motion andactuatesaid second lever to move saidblocking lever to itssaidsecond position, said lost motion being of. sufficient magnitude to permit movemen of saidkey member from said third or said second position to said first position without actuating said second lever.

2; The combination. of claim. 1 in which an overcenter spring p votally connected to said link is provided to hold said blocking lever in either of its said positions;

3'. In a latch mechanism, a keeper-engageable bolt movable toa freeing'position away from the keeper, a dog enga eabl-e with the bolt to hold it a ainst such freeing movement. movable means for releasing said dog from its holding position, locking member rrovable between a blocking position inthepath of movement of said movable means to prevent said releasing movement. and an unblocking position out of said path of movement, over-center means for urging said locking member into either of its positions, second movable means for releasing said dog from its holding position, said dog and locking member having surfaces in adjacent relation when said locking member is in its blocking position and said dog is in its holding position, dog-releasing movement of said second movable means causing engagement of said surfaces to move said locking member toward its unblockin position, whereby said over-center means is permitted to complete the movement of said locking member into its unblocking position.

4. In a latch mechanism, a keeper-engageable bolt movable to a freeing position away from the :eeper, a dog engageable with the bolt to hold it against such freeing movement, movable means for releasing said dog from its holding position, a locking member movable between a blocking position in the path of movement of said movable means to prevent said releasing movement, and an unblocking position out of said path of movement, over-center mean for urging said locking means into either of its positions, actuating means including a lost-motion connection for moving said locking member between its said positions, a second movable means for releasing said dog from its holding position, said dog and locking member having surfaces in adjacent relation when said locking member is in its blocking position and said dog is in its holding position, dog-releasing movement of said second movable means causing engagement of said surfaces to move said locking member toward its unblocking position, whereby said over-center means is permitted to complete the movement of said locking member into its unblocking position, said lost-motion connection being of sufficient magnitude to permit said unblocking movement without disturbing said actuating means.

5. In a latch mechanism, a keeper-engageable bolt movable to a freeing position away from the keeper, a dog engageable with the bolt to hold it against such freeing movement, movable means for releasing said dog from its holding position, a locking member movable between a blocking position in the path of movement of said movable means to prevent said releasing movement, and an unblocking position out of said path of movement, over-center means for urging said locking means into either of its positions, actuating means including a lost-motion connection, a link pivotally connected at one end to said locking member and at the other end to said actuating means for transmitting the movement of said actuating means to said locking member, a second movable means for releasing said dog from its holding position, said dog and locking member having surfaces in adjacent relation when said locking member is in its blocking position and said dog is in its holding position, dog-releasing movement of said second movable means causing engagement of said surfaces to move said locking member toward its unblocking position, whereby said over-center means is permitted to complete the movement of said locking member into its unblocking position, said lost-motion connection being of sufiicient magnitude to permit said unblocking movement without disturbing said actuating means.

6. In a latch mechanism, a keeper-engageable bolt movable to a freeing position away from the keeper, a dog engageable with the bolt to hold 12 it against such freeing movement, movable means for releasing said dog from its holding position, a locking member movable between a blocking position in the path of movement of said movable means to prevent said releasing movement, and an unblocking position out of said path of movement, a second movable means for releasing said dog from its holding position, said dog and looking member having surfaces in adjacent relation when said locking member is in its blockin position and said dog is in its holding position, dogreleasing movement of said second movable means causing engagement of said surfaces to move said locking member toward its unblocking position, a rotatable key-actuated member normally maintained in a first position but rotatable into a second and a third position, a lever having lostmotion connection with said key member, a link pivotally connected between said locking mem-- ber and said lever, said key member being operable upon movement from its said first to its said second position to pass through said lost motion and actuate said lever to move said locking membar to its said blocking position, and operable upon movement from its said first position to its said third position to pass through said lost mo-- tion and actuate said lever to move said locking member to its said unblocking position.

ROLLO MARPLE.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,159,635 Wolfe et a1. Nov. 9, 1915 1,549,603 Murmann Aug. 11, 1925 2,246,782 Dall June 24, 1941 2,301,221 Marple Nov. 1.0, 1942 2,393,147 Cousino Jan. 15, 1946 2,435,987 Tierney et al Feb. 17, 1948 

